A good read; published a few weeks ago... Michael Lombardi: "A Historical Review of U.S. Contributions to the Atomic Redefinition of the SI Second in 1967" http://tf.boulder.nist.gov/general/pdf/2917.pdf /tvb

I have a non-functional HP 4815, don't know if it is the probe or the box. A long time ago, there was a fellow named George Standford (something like that) who repaired these. My old contact information for him is no good. Does anyone know if he is still in business, or if there is any other place that repairs these things? Rick N6RK

Rick Sorry to say I do not know but I do remember an article in EDN I think. The ground connections were riveted and essentially made poor contact after many years. Drilling them out and putting normal screws nuts and lovking lugs in evidently really restored the units. Regards Paul WB8TSL On Tue, Jun 20, 2017 at 2:51 PM, Richard (Rick) Karlquist < richard@karlquist.com> wrote: > I have a non-functional HP 4815, don't know if it > is the probe or the box. A long time ago, there > was a fellow named George Standford (something like > that) who repaired these. My old contact information > for him is no good. Does anyone know if he is still > in business, or if there is any other place that > repairs these things? > > Rick N6RK > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. >

There's a guy on eBay who sells HP stuff (and other) who does certified calibrations and repairs of HP stuff... can't be that hard to find... KN5U is his eBay ID (and call sign?) He calibrated my HP freq counter before sending it to me after I won it on one of his auctions... ______________________ Clay Autery, KY5G MONTAC Enterprises (318) 518-1389 On 6/20/2017 1:51 PM, Richard (Rick) Karlquist wrote: > I have a non-functional HP 4815, don't know if it > is the probe or the box. A long time ago, there > was a fellow named George Standford (something like > that) who repaired these. My old contact information > for him is no good. Does anyone know if he is still > in business, or if there is any other place that > repairs these things? > > Rick N6RK